The objective of this study is to determine the loss in brain substance and the alteration in brain function twelve (12) years after brain damage incurred during the Vietnam War. The resource for this project is a Registry of 1,500 head injuries compiled in the field by military surgeons from 1967 to 1970, and a subsequent Records Review carried out between 1975 and 1979. This study will be accomplished by an in-hospital examination of 1,000 brain-damaged subjects and 200 controls, the latter being utilized as a unique approach to the loss or alteration in structure, i.e., computerized axial tomography and other techniques not available in previous studies of functional sequelae. This project has been terminated at NINCDS, NIH, because of the death of the principal investigator; however, it continues currently at the Walter Reed Army Medical Center under the direction of Lt. Col. David Dillon, Neurosurgeon, USAR, in the Department of Clinical Investigation Service. Another LEN study, "Anatomical Corollary for Computed Tomography" (Z01 NS 02428-02, which please see) has been incorporated into this larger study.